Merge pull request #1436 from bmihelac/fix-1435-msgfmt-output-stdout

fix: po msgfmt output to stdout (#1435)

ale_linters/po/msgfmt.vim

@@ -5,6 +5,6 @@ call ale#linter#Define('po', {
 \   'name': 'msgfmt',
 \   'executable': 'msgfmt',
 \   'output_stream': 'stderr',
-\   'command': 'msgfmt --statistics %t',
+\   'command': 'msgfmt --statistics --output-file=- %t',
 \   'callback': 'ale#handlers#unix#HandleAsWarning',
 \})